Originally Posted by
PaulRivers
...what? The chain doesn't move (side to side or from one gear to another) at all on an IGH. How would it jump?
Chain wears doing so it gets longer. Since there isn't usually a tensioning devices on an IGH bike, the chain get loose pretty quickly and tend to jump when you ride on a bumpy road or something like this. I mostly solved this by doing a DIY adjustable chain jump guard like this one but on the rear sprocket
